In Astrology, the Royal Stars of Persia were regarded as the guardians of the sky in approximately 3000 BCE during the time of the Ancient Persians in the area of modern day Iran.[1] The Persians believed that the sky was divided into four districts with each district being guarded by one of the four Royal Stars.[2] The stars were believed to hold both good and evil power and the Persians looked upon them for guidance in scientific calculations of the sky, such as the calendar and lunar/solar cycles, and for predictions about the future.

The constellations of the Royal Stars were said to be fixed because their positions were close to the four fixed points of the sun's path.[5] The sun was then surrounded by four bright stars at the beginning of every season.[6] From this observation individuals began to denote them the Royal Stars.[6]

By 700 BCE the Nineveh and Assyrians had essentially mapped the ecliptic cycle because of the four stars and were in result able to map the constellations, distinguishing them from the planets and the fixed stars.[5] From this, in 747 BCE the Babylonian King Nabu-nasir adopted a calendar derived from information based on the four stars, one following an eight-year cycle and one a nineteen-year cycle (later adopting the nineteen-year calendar as standard).[7]

The Royal Stars were used primarily for navigation.They were also believed to govern events in the world. Major disasters, breakthroughs, and historical phenomenons were seen as caused by the stars and their alignment in the sky during the time in which the event occurred.[5] When the stars were aligned accordingly, favourable conditions followed, and when they were negatively aligned, disaster was predicted. Because Regulus was the most influential of the Royal Stars, events that took place while Regulus was in dominance were amplified and grave, foreshadowing destruction.

The idea there existed four royal stars of Persia has been analysed and criticized in Popular Astronomy, where it was claimed the idea was largely a relatively modern invention or a misunderstanding of the sources.[8]